Apparatus for the magnetic separation of ore.



G. GRNDAL.

APPARATUS POR .THE MAGNETIC SEPARATION OF ORE.

APPLIOATION FILED mm: 25,1907. 1

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G. GRNDAL. APPARATUS FR TB MAGNETIC SEPARATION 0F ORE. APPLICATION FILEDJUNE 25, 1907.

905,81 5. Patented Dec. 1, 1908. A 3 SHEETS-SHEET Z.

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APILIGATION FILED JUNE 25, 1907. l i

Patented Dec. 1, 1908 s sHBETs-SHET a.

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. INVENTOR www my WITNESSES 'UNITED STATES eUsTAF GRNDAL; or 'DJURsHoLuSWEDEN.

APPARATUS FOR. THE MAGNETIC SEPARATION ,OFl ORE.

Specification of Letters Patent.

Application led June 25, 1907. Serial No. 381,293.

To all whom 'it may concern:

v4Be it -known that I, GUSTA'F GRNDAL, a

subject of the King of Sweden, and resident 'of-"Djursholm, Sweden, haveinvented cery-tain new and useful Improvements-in Apwith iron lamels ischanged for an endless horizontally arranged conveyer band made of amagnetically indifferent material, the under part of said band movingabove and at a suitable .distance from the surface of the currentcontaining theV suspended material and between the water and a sy-stemof electromagnets with elongated pole pieces 'which is substituted forthe magnet pole having an elongated edge. The electromagnets of` saidsystem must have such a position relatlvely to the inner side of theband that the end surfaces of their pole pieces directed towards theband are parallel to the band and the magnet system must extend so faralong the band as to reach over a vessel adapted to receive theconcentrate sticking to the underside of the band when it has comebeyond the sphere of action of the magnet system and falls down. Theapparatus, 1n what concerns the conduction of the current of suspendedmaterial under the endless band is arranged similarly to the apparatusdescribed in the Patent No. 812170 which patent is referred to and theoperation is also the same.

In the accompanying drawings'there are shown diagrammatically two formsof the apparatus according to'the invention, Figure l being alongitudinal section of a double apparatus having the band moving in thedirection of the current of suspended material and Fig. 2 beingl a crosssection on line 2-2 Fig. 1. Fig. 3 represents a single apparatus in asection on line 3 3 of Fig. 4i the band moving at right angles to thedirection of the current of suspended material and Fig. 4 is a section`thereof on line 4 4 of F ig. 3.

The same reference letters indicate the same. or corresponding parts.

Patented Dec. 1, 1908.

rotated by means of a belt connection from a motor. vD7 D are thesystems of electromagnets. Beneath the band there are several vesselsand compartments having the necessary inlets and outlets. E is a feedconduit for'the-material suspendedin Water to be separated. Beneath theoutlet of said conduit E there-is a vessel F. in the bottom of which awater vconduit H provided with a regulating cock Gr opens. separated bymeans of a partition c' which is lower than the side walls J andpreferably has the form shown in Fig. 1 from a vessel K from the bottomof which issues an outlet pipe M yprovided with a cock L. The vessel Kis provided .with an overflow N on the other side of which there is adischarge 0 and `on the other side thereof a transverse partition P onthe other side of which there is a similar set of vessels F, K and Oarranged in the same mannerV relatively to the electromagnet system D asthe vessels F, K and O relatively to the electromagnet system D andprovided with corresponding pipes H', M provided with regulating cocksG', L. On the other side of the partition P The vessel F is' there is avessel R provided withfan opening f Q. S and S indicate water. conduitsprovided with nozzles T, T directed towards the underside of the endlessband.I With some movement has been imparted to the endless band in thedirection of thel arrow the finely divided ore to be separated is ledinto the compartment F by a conduit E. This compartment aswell as thecompartment K are illed with and traversed by a current of water whichis fed from the pipe H in the required' quantity. This water keeps theore powder coming from the conduit E in the vicinity of the surface andcarries the powder with-it over the partition z' and over thecompartment K and also over the overflow N and discharges through the`outlet O. During this conveying of the o'e powder beneath the magnetsthe separation is ef-` fected in three grades in the following manner.The particles ofpure ore are attracted towards the band and drawnupwards from out of the water sticking'to the bandas long as it pressesunder the magnet system z'. o. over and past the discharge O after whichthey fall down and 'are gathered. The less pure ore particles rest 'onthe water surface and cannot penetrate it but follow the current ofwater and are discharged through the outlet O and gathered for furthertreatment. The gangue or the particles not attracted by the magnetsystem sinkfto the bottom of the compartment K and are dischargedthrough the pipe M.

The operation just described is the one occurring in a single apparatushaving only one magnet system vbut under certain conditions itmay beadvantageous to further purify the ore. particles drawn upwards out ofthe water towards the band, as less pure particles may adheremechanically, and for this purpose a double apparatus is used as shownin the Figs. l and 2. In the said double apparatus when the band withad# hering ore particles has passed the magnet: system D the particlesleave the band and fall down into the vessel F', lWater jets from thepipe S ,facilitate this 'falling down of the ore particles. rl`hroughthis vessel F passes a. regulated current ot' water from the pipe H in"the same manner as is the case in the vessel F. The powder is carriedand conveyed by this current until it arrives under the second magnetsystem D when the pure ore particles, being in the meantime separated bythe water from therlcss pure particles that may have followed along withthem are drawn upwards out of the water b` this magnet system and arecarried by the band beyond the partition P', fall down into the vessel Rand are removed through the opening Q. later jets from the pipe Scleanse the band. The less magnetic particles are discharged with thewater through the outlet O' and the not attracted particles fall downinto the vessel K and are discharged through the pipe M.

From the foregoing description of the operatiouthe operation of theapparatus according to the Figs. 3 and 4 is evident, the only ditferencebeing that the endless band B in consequence ot its arrangement convcysthe ore particles drawn out from the current of water laterally to saidcurrent and these ore particles fall down into the vessel l?.

lf the finely powdered ore does not contain any middlings the cock L maybe set in such a manner that the water surface is kept as shown on theFigs. 3 and 4 and no water is run'iing over the overflow N. Saidoverflow for collecting the middlings can then be omitted.

In the forms of apparatus shown the pole pieces of the magnet systemsare lying with 5 their ends parallel to the lower part of the endlessbaud but the same etiect is also obtained if one or more pole piecesshould be placed at a greater distance from-the lower part of the bandif only the corresponding magnets are made more powerful than the other.

I claim: f

l. An apparatus for the magnetic separation oi ore comprising a vesselto receive the mixed material, means for leading the latter thereto, ayconduit for water opening into said vessel, a second vesselcommunicating with the latter by Aan overflow and provided with anoutlet and an overflow discharge, in combination with a magnet'above thevessels and extending beyond the'overtlow between the same, togetherwith a band interposed between the surface ot' the water in said vesselsand said magnet and extend-- ing over the second vessel and its overflowdischarge and means to move said band, substantially as and for thepurpose described.

2. An apparatus for themagnet'c separatien of ore comprising a vessel toreceive the mixed material, means for leading thelatter thereto, a,conduit for 'water opening into said vessel, a second vesselcommunicating with the latter by an overtiow and provided with an outletand an ovcrow discharge, in combination with a. second set of vesselssimilarly arranged and placed in tandem therewith together with a magnetabove each set of vessels extending beyond the overflow between themembers ot each set, and a band interposed between said magnets and thesurface of the water in said vessels and extending over the said vesselsand overflow discharges, whereby the material. separated in the firstgroup of vessels may be transferred to the second set, and 'means tomove said hand, substantially as described.

23. An apparatus for the magnetic separation oi" ore, comprising avessel to receive the ore. a conduit for a suspension liquid openinginto said vessel, a second `vessel communicating with the latter by anoverflow and provided with an outlet and an overllow discharge, incombination with a magnet or magnets arranged above the overtiow betweensaid vessels andex'tending beyond the second vessel and its overflowdischarge, together with a movable bandinterposed between the surface oithe water in said vessels and said magnet system and extending over thesecond vessel and its overflow discharge. substantially as and vtor thepurposes described.

lu testimony whereof l have signed my' name to 'this specification, twosu srrilnng witnesses.

GUSTAF ll'tDL.

in the presence of lVitnesses (lun. Frumento,A HJALM'AR Znrrnns'rnon.

